Slitter device for wire insulation or the like



T. A. HARKINS Ian., I@ 1951 SLITTER DEVICE FOR WIRE INSULATION OR THE LIKE Filed Oct. 6, 1947* INVEN 0R. z/

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Patented Jan. 16, 1951 UNITED STATES PATENT ortica SLITIER DEVE-CE FOR WIREINSULATION 0R LIKE Thomas A. Harkins, Los Angeles, Calif. Application October 6, 1947, Serial No. 778,202

(cl, en -.91)

n 7 Claims.v l

My invention relates to slitting devices yand more particularly to apparatus adapted for cutting a slit within the insulation of `wire covering` Accordingly an object of my invention is to provide a slitting tool or device, having a housing mounted upon a suitable handle, said housing having a bracket Vprovided witha suitable roller adapted for guiding the wire or cable thereover, alsa-said housing having a retractable plunger means provided with a slitting'tool or knife, with which a slit may be cut within the insulation of said wire or cable, when pressed into said insulation and-pulled lengthwise over said'roller.

Another object of my `invention is tol provide said slitting tool with a self-centering and selilocating adaptor provided with said slitting tool or knife, and adapted for positioning and for holding said knife and its cutting edge at the center of said insulation, and when said wire or cable is placed over the guiding roller, thereby preventing oli-center cutting in said insulation and also preventing the damage to a wire en,- cased therein. c v A further object of myinvention is to provide said slitting tool with a retractable plunger means and a frictionally engaging brake means, adapted for holding said plunger means in locked position when `set and when cutting the slit within the insulation of said wire or cable.

Another object of my invention is to provide Ysaid plunger means of. said slittingtool with ,a

depth gage ring, which is adjustably mounted thereon, and thereby providing means for regulating and controlling the depth of the slit in said insulation of the wire or cable. 1

A further object of my invention is to provide said slitting tool or device with a retractable plunger means, which is equipped with a removable and adjustable slitting tool or knife, further, said device having a plunger engaging brake meansv adapted for holding said plunger means together with said slitting knife in a set position, and also, having suitable means for releasingsaid plunger means from its slit cutting position into its upwardly normal position, and in addition said brake release means havinga regulating pin associated therewith, for allowing said plunger engaging brake means to be held in an engaging position when set for cutting a predetermined depth in the wire or cable insulation, or, for neutralizing the action of saidV brake means, whereby any desired depth of slit in said wire orY cable insulation may be cut, and thereby controlling saidslit cutting operation when saidzwire ora-cable is coatedwithan irregular insulation,

l said slitting tool Tor device with a retractable plunger means, said plunger having lspring means associated therewith for maintaining the same in 2 the uppermost position, and in addition said plunger having means for regulating a downward travel of said plunger, thereby preventing the knife cutting edge from penetrating deeper into the insulation of a wire or cable, than the required depth originally set by means of said regulating means.

Another.. object of my invention is to provide said retractable plunger means with a removable ancl interchangeable cartridge means, said cartridge means having a slitting knife adjustably mounted therein, also said plunger means havingan electing spring mounted` therein for ejecting said cartridge means from its position when released by the mounting screw,4 and therebyfacilitating the handling and knife edge length setting operation, when necessary or required.

My invention also has for its objects to pro- Vide such means that are positive in operation, convenient in Vuse, easily installed in a working position and easily disconnected therefrom, economical in manufacture, relatively simple, and of general superiorityand serviceability.

The inventlonalso comprises novel details ci construction and novel combinations and arrangements of parts, which will more fully appear in the course of the iollowing'description. However, the drawings merely show and the following description merely describes embodiments of the present invention, whichY are given by'way oi illustration only.

Reference is now had to the accompanying drawings, in which the sLmilar reference characters denote the same parts.

In the drawings: l Fig. l is the side elevational View of the slitter device.

Fig. 2 is the frontelevational view thereof.

Fig. 3 is a fragmentary and slightly enlarged sectional view of the housing, showing the retractable plunger vand the locking mechanhm in position, taken on the line 3-3oi Fig. 2.

Fig. 4 is another sectional View of the plunger, taken on the line 4 4 of Fig. 3.

Fig. 5 is a fragmentary sectional view of the lock ring pivot section, taken on the line 5--5 of Fig. 3.

Fig. 6 is another fragmentary sectionalview thereof, showing the lock ring trip lug member, taken on the line 6-5 of Fig. 3.

Fig. '7 is a horizontal sectional view of the housing and the plunger, showing the locking ring in position, taken on the line 'I-l of Fig. 4.

Fig. 8 shows another horizontal sectional view of said housing, taken in the directionvof the arrow 3 8, of Fig. 3.

Fig. 9 is a fragmentary sectional view of the tripper pin member, showing the same in relation to the mounting pin, taken on the line 9-9 of Fig. 3.

Fig. lO'is a horizontal sectional View ofthe plunger member, showing the slots in relation to the mounting pin, taken on the line ID--I of Fig. 3.

Fig. 11 shows the bottom View of the housing and the plunger member, showing a plate mounted upon the end of the housing, and showing the structure in a modied form.

Fig. l2 shows a fragmentary sectional and partly vertically elevational view of the plunger control and release mechanism of the device, showing the same in nearly the same position as disclosed in Fig. 3, and showing the same in a .modified form.

` Fig. 13 is a horizontally sectional and partly Yfragmentary View of the tripper pin extension, taken on the line I3-I3 of Fig. 12.

'Describing my invention more in detail, in itsY broader aspects, said invention comprises, a housing 2 having a suitable extension 4, the upper section oi which is provided with a suitable handlemember E, which extends outwardly and rear- -wardly therefrom, as shown. y Y

Said housing 2 is provided with a suitably bored out section .3, wherein a plunger member I0 is slidablyv mounted,-and which is held in position by means of. a pin member` i2 passingthrough a pair of locating slots I4 which extend intoV the upper section I0 of said plunger, said slots I4 being adapted for guidingsaid plunger member into a downward and retractable positionand also for holding said plunger member I in place.

Said pin member I2 is provided with a threaded head I5 which is secured in said housing 2, while the pin end I8 extends into said housing for engaging a milled out section 25, which is disposed within the shank member 22 of a tripper pin member 24, the operation andthe purposedof which will be presently described.

The plunger member I0, in its preferred form,

is made out ofrsuitable tubing, and comprisesthe upper end section 26 which terminates'withV a plunger cap member 28, also, said plunger having the outer surface section thereof provided with a suitablev thread 33, which is adapted for engaging and for mounting a gage ring 32 thereon, so that the same may be adjusted to anylsuitable position and thereby regulatingv the downsaid plunger member I0.

The lower section 34, of said plunger member Ie, is provided with a suitable locating bushing f ward movement and the downwardposition of Said bushing 36 is held in position and within said plunger member I0 by means of a suitable mounting pin member 42, as shown.

Said slitting knife 4E) is also held` in position by means of a self-centered cartridge member 44, the lower end of which is tapered as at 46, for engaging the end edge of said plunger member I0 at said lower section 34, while the upper end 48, of said cartridge, is fitted into said bushing 36, and wherein said cartridge member 44 is held in position by means of a set screw member 50, as shown in Fig. 4.

It may then be noted, that said knife 4G is provided with a wide shank 52 at the upper part or section thereof, which fits snugly into the lower section 34 of said plunger member I6, and thereby preventing said knife from tilting when a pressure is applied thereto, and while cutting a heavy cable sheath, lead covering, or heavy synthetic rubber, plastic or the like.

In order Vto adjust the position ofv the knife point 54, said cartridge 44 Vis providedwith a suitable adjusting set screw 55, and also, for facilitating the removal ofsaid cartridge from its set position, a suitable pressure spring' 58 is provided, as shown in Figs. 3 and 4, and which is supported in its compressed position by means of said pin member 42.. Y

Y Also, for holding and for maintaining an uppermost position ofY said plunger member I0, a suitable spring member BIJ is provided within said upper end section 26, one end of which resting against the underside section of said cap member 28, while the other end'thereof bears upon said pin member I2, as shown. Y

In order to hold said plunger member I0 in any set position, when pressed downwardly, a suitableV lock ring 62 is provided in saidV housing 2,A

`which is disposed within a groove 80, as shown.

The inside .bore of said ring 62 isslightly larger than the outside diameter of said plunger member II), which allows a slight angular position thereover while the pivot end E5 is held in posi- .Y tion and the trip lug member thereof is pressed upwardly by said Vspring 18, which Vimposes a binding friction upon said plunger member I0 and thereby holding said plunger in anyV set position. Y

In order to release the binding frictionof saidV lock ring 62 then said tripperV pin member 24 is employed, which is mounted within a suitable socket 82, seeFig. 3, of Vwhich the lowermost vextension`34 engages said triplug member 68,

said milled out section 20 including said recess 10. and said socket 82 having sufcient clearance, so that when vpressing the tripper head 86 downwardly, then the frictional binding of said lock ring 52 over said plunger member I is released, whereby the compressed spring member E causes saidplunger to retract into its uppermost normal position. i

For guiding and for holding a wire or cable in place and beneath saidknife'point 54, a suitable step roller 88 is' provided, which is. mounted bracket .92 and which is housiwithin. the loop 90 of a heldin position upon the-side section of said ing 2, by means of suitable screwsf94'.

For preventing said bracket 9'2 4vfrom shifting out of alignmentlthe upper section thereof is mounted within a suitable recess 96, and for preventing dragging ofy thev wire orcable when placed Overfsaid rQ1ler;88,;-a suitablepin 98 `is provided for mounting said roller thereon-and. for; permitting said rollertorevolve freely thereover.

As shown in' Fig. l2, said tripper'pin 24, in its construction and operation, issshown in al modified. form,rior allowing said knife particularly theknife point 54, vto be set. at avpredetermined pc'sition, and also, for Vallowingthe use vof said knife point in special leases, when/the insulation of wire or cable is of irregular shape, structure, thickness or conguration.

To that end, said shank 22 'of said tripper` pin, is provided with a recess |04, which, in addition of allowing said pin end IB to lhold the same in place and position, said pin 24 is allowed to be turned in the socket member 82.

Also, the extension 84 of said tripper pin 24 is provided with a suitable arresting groove |06 for accommodating therein a screw point |08 extending out of a set screw member ||0, which, in this position and location, said ring 64 is tilted downwardly, remainingv in a neutral and inactive position, and thereby allowing said plunger l0 to remain free of frictional resistance afforded by said ring 84, and in the manner hereinbefore described.

When said ring 64 is held in a neutral position, then said plunger I0 may be pressed downwardly to any desired point of location, the position of which may be regulated by the thumb pressure imposed upon said cap member 28, and thereby allowing said slitting knife 40 to cut into the insulation of wire or cable, of irregular shape, thickness or conguration.

I,accordingly, do 'notpropose to be limited to the exact details of construction herein shown uon the drawings and described in the specificay mounted insaid plunger, a slitting knife in said When it is desired to secure a predetermined depth cut control of said plunger I0, said tripper pin 2li is turned in said socket 82, to an approximate 90 degrees, which allows said screw point |08 to enter a longitudinal slot ||2, thereby releasing said ring 64 from its set and inactive position, allowing said ring to pivot upon said pivotend E5, the position of which being supported by said spring I8, so that a frictional grip upon the plunger I 0 may be had, in a similar mannel` as previously described. i

Said longitudinal slot l |2l is arranged to permit a downward movement of said tripper pin 24, which movement is used for releasing said grip on said plunger member 0, and thereby allowing said plunger to be retracted into its normal upward position, when released, the upward movement thereof being supported by said spring member Sii.

In addition, it may be noted, that in place of employing said plugmember 16, which is used for holding said lock ring member 62 in position, and also for guiding and formaintaining a rigid position of Said plunger I0, when in its downward and lowermost position, said housing 2, at its extension 4, may, if so desired, be provided with a suitable locating plate |38, which is held in place by means of screws |40, and which in use and application will accomplish and will serve the same useful purpose as hereinbefore pointed out.

While I have thus described my invention with Vgreat particularity, it will be clear that the same may be modified throughout a Wide range.

cartridge, a frictional ring means in said housing, a spring in said housing for supporting one end of said ring means and for holding the same in a frictional engagement with said retractable plunger member, thereby holding said plunger member in position when pressed downwardly, a tripping means in said housing for releasing said plunger member from the downwardly held position, and a spring member in said plunger member for forcing said plunger member upwardly and into its normally upward position.

2. In a slitting tool of the class described, as disclosed in claim 1, wherein, said tripping means is provided with guiding means for guiding said tripping means when releasing said frictional ring means from its frictional engagement and locked position over said plunger memberLand means in said tripping means for neutralizing the grip imposed upon said plunger member by said ring means, thereby allowing said plunger mem'bcrto be pressed downwardly and into a cutting position, and also, for releasing said plunger member into its normally upward position.

3v. A slitting tool of the class described, comprising, a housing, a handle extending outwardly from said housing, a retractable plunger means mounted in said housing, a lock ring means in said housing for frictionally engaging said plunger means, a bracket means connected to said housing and having a roller revolubly mounted therein for holding a wire or cable in position, a slitting knife in said plunger means for slitting the insulation in said Wire or cable, and tripper means in said housing for releasing said locking ring means from the frictional position over said plunger means and thereby releasing said plunger means from the downwardly set position,

4. In a slitting tool of the class described comprising a, housing, a handle extending sidewardly from said housing, a retractable plunger means slidably mounted in said housing, means in said plunger for maintaining the retractable position of said plunger, and means in said housing for frictionally engaging said plunger and* thereby holding same in any set position,.the combination of, a locating bushing in the lowermost end of said plunger, a locating groove in said bushing, and a concentric'cartridge means in said plunger carrying a slitting knife and mounted in saidv bushing thereby locating the cutting position of said slitting knife, and means in said plunger for holding said cartridge in position.

5. In a slitting tool of the class described, as

vdisclosed in claim 4, wherein an adjustable set v screw is provided in said cartridge, for adjusting the knife point of said slitting knife, and spring means in said locating bushing for ejecting saidY cartridge fromits set'position, when released by said holding means in said plunger.

6. In a slitting tool of the class described, as disclosed in claim 4, wherein, a. tripper pin means is provided in said housing for releasing said frictionally engaging means for said plunger, and thereby releasing said plunger and said slitting knife from the downward position of said plunger and the cutting position 0f said knife, respectively. Y

7. In a slitting tool of the class described, .as disclosed in claim 4, wherein a plug` member is provided in said housing, a boss vmember in said plug for holdingsaid frictionally engaging ring means in tiltable position, a groove in said plug member, and resilient means in said groove whereby Vthe ppermosttilted position of said frictionally engaging plunger means may be maintained and thereby holding said plunger member in its setrposition.V

THOMAS A. HARKINS.

REFERENCES CITED The following references are of record in the le of thispatent:l Y

UNITED vSTAT'VS j PATENTS 1 Stone May 25, 1948V 

